<div id="site-nav" class='navbar'>
  <div class='navbar-inner'>
    <div class='container'>
      <a class='brand' routerLink='/topic'>
        <img src="images/logo.png" />
      </a>

      <form id='search_form' class='navbar-search' action="/search">
        <input type='text' id='q' name='q' class='search-query span3' value=''/>
      </form>
      <ul class='nav pull-right'>
        <li><a routerLink='/topic'>首页</a></li>
        <li>
          <a routerLink='/message'>
            未读消息
            <span class='big messages_count'>{{ notReadMessageCount + ""}}</span>
          </a>
        </li>
        <li><a routerLink='/getstart'>新手入门</a></li>
        <li><a href='https://angular.cn/' target='_blank'>官方文档</a></li>

        <li><a routerLink="/about" target="">关于</a></li>
        <li *ngIf="isShow"><a routerLink='/setting'>设置</a></li>
        <li *ngIf="isShow" class="logout-li" >
          <a  rel="nofollow" (click)="signout()">退出</a>
        </li>
        <li *ngIf="!isShow" class="register-li"><a  routerLinkActive="active" [routerLink]="['/sing/register']">注册</a></li>
        <li *ngIf="!isShow" class="login-li" ><a  routerLinkActive="active" [routerLink]="['/sing/login']" >登录</a></li>
      </ul>
      <a class="btn btn-navbar" id="responsive-sidebar-trigger">
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
      </a>
    </div>
  </div>
</div>
